INFLUENCE OF WOOD SAW DUST AND WASTE GLASS ADMIXTURE ON SELECTED PROPERTIES OF FIRED CLAY BRICKS FOR MASONRY

Abstract

This study investigated the effect of mahogany wood sawdust (WSD) and waste glass (WG) addition on the properties and cost of producing fired clay bricks for construction of houses. Materials used were clay, WSD and WG. Brick samples were produced in batches and labeled as samples A (with no additives), B, C, D, E, F, G and H. Each sample of B, C, D, E, F, G and H contained 5% fixed amount of WSD, and 10, 15, 20, 25, 30, 35 and 40% of WG respectively. Brick samples produced were tested for apparent porosity, bulk density, compressive and flexural strengths, thermal conductivity and wear. Results obtained showed that as waste glass content increased in the samples, bulk density and compressive strength increased due to enhancement of densification and compaction within the samples. Thermal conductivity also increased as waste glass increased due to reduction in porosity and reduced inter-particle distance. The value of flexural strength increased with WG content but at 35% and 40%, the value reduced. This is as a result of an increase in brittleness as waste glass content increased which increased stress concentration in the samples, hence leading to a reduction in flexural strength. Also, it was observed that the increase in the content of the waste glass led to a reduction in the value of apparent porosity and wear depth due to improved cohesion between particles in the bricks. Comparing results obtained with existing standards and considering the cost of production, 5% WSD and 25% WG addition, with apparent porosity of 26.3%, compressive strength of 17.5 MPa, thermal conductivity of 0.32 W/mk and wear depth of 1.72 mm is recommended for construction purposes.